Soqotri

dḳḳ - to become thin (LS 133)

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.