Arabic

dqq - to break, to crush; to knock; to be thin, slender, small, minute, fine (Lane 895)

daqīq- ‘slender, fine; flour’, diqq- ‘slender, fine’ (Lane 896).

PS
*dḳḳ - to crush, to pound; to be ground finely, to be fine, minute (EDA II)

For the frequent in individual Semitic languages semantic shift ‘to be ground finely, to be fine, minute’ > ‘to be little, smalľ in Indo-European languages see Buck 1949, 880ff.