"head movement" meaning in English

{
  "forms": [
    {
      "form": "head movements",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "head movement (countable and uncountable, plural head movements)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Linguistics",
          "orig": "en:Linguistics",
          "parents": [
            "Language",
            "Social sciences",
            "Communication",
            "Sciences",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Movement of a word from the head of one maximal projection to the head of another maximal projection above the first one (i.e., such that the destination head c-commands the original head)."
      ],
      "hyponyms": [
        {
          "word": "T-to-C movement"
        },
        {
          "word": "V-to-T movement"
        }
      ],
      "id": "en-head_movement-en-noun-FmKSnEX0",
      "links": [
        [
          "c-command",
          "c-command"
        ]
      ],
      "raw_glosses": [
        "(syntax) Movement of a word from the head of one maximal projection to the head of another maximal projection above the first one (i.e., such that the destination head c-commands the original head)."
      ],
      "related": [
        {
          "word": "wh-movement"
        }
      ],
      "synonyms": [
        {
          "word": "head-to-head movement"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "sciences",
        "syntax"
      ]
    }
  ],
  "word": "head movement"
}

{
  "forms": [
    {
      "form": "head movements",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "head movement (countable and uncountable, plural head movements)",
      "name": "en-noun"
    }
  ],
  "hyponyms": [
    {
      "word": "T-to-C movement"
    },
    {
      "word": "V-to-T movement"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "wh-movement"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with non-redundant non-automated sortkeys",
        "English uncountable nouns",
        "en:Linguistics"
      ],
      "glosses": [
        "Movement of a word from the head of one maximal projection to the head of another maximal projection above the first one (i.e., such that the destination head c-commands the original head)."
      ],
      "links": [
        [
          "c-command",
          "c-command"
        ]
      ],
      "raw_glosses": [
        "(syntax) Movement of a word from the head of one maximal projection to the head of another maximal projection above the first one (i.e., such that the destination head c-commands the original head)."
      ],
      "tags": [
        "countable",
        "uncountable"
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "sciences",
        "syntax"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "head-to-head movement"
    }
  ],
  "word": "head movement"
}