Brown-Driver-Briggs
חִין noun [masculine] חִין עֶרְכּוֺ Job 41:4 the
grace of his proportions ( =
חֵן Aramaic
חִנָּא) so AV RV Thes De Volck Da and others; meaning not very appropriate in context (description of crocodile); but nothing better has been proposed; see suggestions in Di.