"subdrill" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sub",
        "3": "drill"
      },
      "expansion": "sub- + drill",
      "name": "prefix"
    }
  ],
  "etymology_text": "sub- + drill",
  "forms": [
    {
      "form": "subdrills",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "subdrill (plural subdrills)",
      "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 terms prefixed with sub-",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2013, David Jonassen, Instruction Design for Microcomputing Software",
          "text": "Learners can go through the series of subdrills and review old drills in a systematic manner. The various subdrills may be selected by the learner from a menu such as that shown in Fig. 4.11.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A training exercise forming part of a larger training exercise or system."
      ],
      "id": "en-subdrill-en-noun-EaPIIAIY"
    }
  ],
  "word": "subdrill"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sub",
        "3": "drill"
      },
      "expansion": "sub- + drill",
      "name": "prefix"
    }
  ],
  "etymology_text": "sub- + drill",
  "forms": [
    {
      "form": "subdrills",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "subdrill (plural subdrills)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with sub-",
        "English terms with quotations",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "2013, David Jonassen, Instruction Design for Microcomputing Software",
          "text": "Learners can go through the series of subdrills and review old drills in a systematic manner. The various subdrills may be selected by the learner from a menu such as that shown in Fig. 4.11.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A training exercise forming part of a larger training exercise or system."
      ]
    }
  ],
  "word": "subdrill"
}