'angulus' originates from Latin, specifically the word 'angulus,' where the Indo-European root 'ang-/ank-' meant 'to bend; a bend or curve.'

'Angulus' was preserved in New Latin scientific terminology and was subsequently adopted unchanged into English anatomical and medical usage as 'angulus'.

Initially, it meant 'corner; angle,' and this sense has remained largely the same, now used primarily in anatomical contexts.