D defs.my
Entry 1 sense Webster, 1913

Dia-

· Di·a- · IPA /daɪə/
01 A prefix denoting through; also, between, apart, asunder, across. Before a vowel dia- becomes di-; as, diactinic; dielectric, etc.
  1. 1.
    A prefix denoting through; also, between, apart, asunder, across. Before a vowel dia- becomes di-; as, diactinic; dielectric, etc. Also: di-