"a-" meaning in Old French

{
  "etymology_templates": [
    {
      "args": {
        "1": "fro",
        "2": "la",
        "3": "ad"
      },
      "expansion": "Latin ad",
      "name": "inh"
    }
  ],
  "etymology_text": "From Latin ad, which was often reduced to a- in compounds.",
  "head_templates": [
    {
      "args": {
        "1": "fro",
        "2": "prefix"
      },
      "expansion": "a-",
      "name": "head"
    }
  ],
  "lang": "Old French",
  "lang_code": "fro",
  "pos": "prefix",
  "senses": [
    {
      "glosses": [
        "indicating movement towards something"
      ],
      "id": "en-a--fro-prefix-KHIUfKPc",
      "tags": [
        "morpheme"
      ]
    },
    {
      "categories": [
        {
          "_dis": "2 0 0 0 0 2 0 1 0 0 0 0 1 0 0 0 1 0 0 0 1 1 3 4 2 2 0 0 1 1 0 2 2 0 0 1 1 2 0 0 4 3 2 4 3 0 0 0 1 0 2 2 2 1 5 0 0 0 0 0 0 0 2 2 2 1 1 0 2 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 4 3 1 0 0 1 0 2 3 3 0 0 0 0 0 0 1 0 0 2 0 1 0",
          "kind": "other",
          "name": "Pages with 47 entries",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "2 0 0 0 0 2 0 1 0 0 0 0 2 1 0 1 1 0 0 0 1 1 2 3 1 2 0 1 1 2 0 2 2 0 1 1 1 2 0 0 3 2 1 3 3 0 0 0 1 0 2 2 2 1 6 0 0 0 0 0 0 0 2 2 1 1 2 0 1 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 3 0 0 0 0 1 5 4 2 0 0 1 0 2 2 2 0 0 0 0 1 1 2 0 0 3 0 1 0",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "14 80 1 4",
          "kind": "other",
          "name": "Old French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "indicating a change of state"
      ],
      "id": "en-a--fro-prefix-GCWHPHZy",
      "raw_glosses": [
        "(by extension) indicating a change of state"
      ],
      "tags": [
        "broadly",
        "morpheme"
      ]
    },
    {
      "glosses": [
        "intensifying prefix"
      ],
      "id": "en-a--fro-prefix-VKotgAUy",
      "tags": [
        "morpheme"
      ]
    },
    {
      "alt_of": [
        {
          "word": "es-"
        }
      ],
      "glosses": [
        "alternative form of es-"
      ],
      "id": "en-a--fro-prefix-lTyCo4jk",
      "links": [
        [
          "es-",
          "es-#Old_French"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "morpheme"
      ]
    }
  ],
  "word": "a-"
}

{
  "categories": [
    "Old French entries with incorrect language header",
    "Old French lemmas",
    "Old French prefixes",
    "Old French terms derived from Latin",
    "Old French terms inherited from Latin",
    "Pages with 47 entries",
    "Pages with entries"
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "fro",
        "2": "la",
        "3": "ad"
      },
      "expansion": "Latin ad",
      "name": "inh"
    }
  ],
  "etymology_text": "From Latin ad, which was often reduced to a- in compounds.",
  "head_templates": [
    {
      "args": {
        "1": "fro",
        "2": "prefix"
      },
      "expansion": "a-",
      "name": "head"
    }
  ],
  "lang": "Old French",
  "lang_code": "fro",
  "pos": "prefix",
  "senses": [
    {
      "glosses": [
        "indicating movement towards something"
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "glosses": [
        "indicating a change of state"
      ],
      "raw_glosses": [
        "(by extension) indicating a change of state"
      ],
      "tags": [
        "broadly",
        "morpheme"
      ]
    },
    {
      "glosses": [
        "intensifying prefix"
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "alt_of": [
        {
          "word": "es-"
        }
      ],
      "glosses": [
        "alternative form of es-"
      ],
      "links": [
        [
          "es-",
          "es-#Old_French"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "morpheme"
      ]
    }
  ],
  "word": "a-"
}