"lepto-" meaning in English

{
  "antonyms": [
    {
      "word": "eury-"
    },
    {
      "word": "platy-"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "grc",
        "3": "λεπτός",
        "4": "",
        "5": "thin"
      },
      "expansion": "Ancient Greek λεπτός (leptós, “thin”)",
      "name": "bor"
    }
  ],
  "etymology_text": "Borrowed from Ancient Greek λεπτός (leptós, “thin”).",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prefix",
        "head": "",
        "sort": ""
      },
      "expansion": "lepto-",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "lepto-",
      "name": "en-prefix"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prefix",
  "senses": [
    {
      "glosses": [
        "thin, fine, narrow, slender"
      ],
      "id": "en-lepto--en-prefix-16cRbm2a",
      "links": [
        [
          "thin",
          "thin"
        ],
        [
          "fine",
          "fine"
        ],
        [
          "narrow",
          "narrow"
        ],
        [
          "slender",
          "slender"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Physics",
          "orig": "en:Physics",
          "parents": [
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "_dis": "5 56 39",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "derived": [
        {
          "_dis1": "8 92",
          "word": "lepta"
        },
        {
          "_dis1": "8 92",
          "word": "leptin"
        },
        {
          "_dis1": "8 92",
          "word": "leptocephalus"
        },
        {
          "_dis1": "8 92",
          "word": "leptokurtotic"
        },
        {
          "_dis1": "8 92",
          "word": "lepton"
        },
        {
          "_dis1": "8 92",
          "word": "leptoprosopic"
        },
        {
          "_dis1": "8 92",
          "word": "leptosome"
        },
        {
          "_dis1": "8 92",
          "word": "leptotene"
        },
        {
          "_dis1": "8 92",
          "word": "leptonema"
        },
        {
          "_dis1": "8 92",
          "word": "Leptospira"
        },
        {
          "_dis1": "8 92",
          "word": "leptospirosis"
        }
      ],
      "glosses": [
        "lepton"
      ],
      "id": "en-lepto--en-prefix--hFvunaA",
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "lepton",
          "lepton"
        ]
      ],
      "raw_glosses": [
        "(physics) lepton"
      ],
      "related": [
        {
          "_dis1": "3 97",
          "word": "meso-"
        },
        {
          "_dis1": "3 97",
          "word": "steno-"
        }
      ],
      "synonyms": [
        {
          "_dis1": "8 92",
          "tags": [
            "before-vowel"
          ],
          "word": "lept-"
        }
      ],
      "tags": [
        "morpheme"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "word": "lepto-"
}

{
  "antonyms": [
    {
      "word": "eury-"
    },
    {
      "word": "platy-"
    }
  ],
  "categories": [
    "English entries with incorrect language header",
    "English lemmas",
    "English prefixes",
    "English terms borrowed from Ancient Greek",
    "English terms derived from Ancient Greek"
  ],
  "derived": [
    {
      "word": "lepta"
    },
    {
      "word": "leptin"
    },
    {
      "word": "leptocephalus"
    },
    {
      "word": "leptokurtotic"
    },
    {
      "word": "lepton"
    },
    {
      "word": "leptoprosopic"
    },
    {
      "word": "leptosome"
    },
    {
      "word": "leptotene"
    },
    {
      "word": "leptonema"
    },
    {
      "word": "Leptospira"
    },
    {
      "word": "leptospirosis"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "grc",
        "3": "λεπτός",
        "4": "",
        "5": "thin"
      },
      "expansion": "Ancient Greek λεπτός (leptós, “thin”)",
      "name": "bor"
    }
  ],
  "etymology_text": "Borrowed from Ancient Greek λεπτός (leptós, “thin”).",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prefix",
        "head": "",
        "sort": ""
      },
      "expansion": "lepto-",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "lepto-",
      "name": "en-prefix"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prefix",
  "related": [
    {
      "word": "meso-"
    },
    {
      "word": "steno-"
    }
  ],
  "senses": [
    {
      "glosses": [
        "thin, fine, narrow, slender"
      ],
      "links": [
        [
          "thin",
          "thin"
        ],
        [
          "fine",
          "fine"
        ],
        [
          "narrow",
          "narrow"
        ],
        [
          "slender",
          "slender"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "categories": [
        "en:Physics"
      ],
      "glosses": [
        "lepton"
      ],
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "lepton",
          "lepton"
        ]
      ],
      "raw_glosses": [
        "(physics) lepton"
      ],
      "tags": [
        "morpheme"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "synonyms": [
    {
      "tags": [
        "before-vowel"
      ],
      "word": "lept-"
    }
  ],
  "word": "lepto-"
}