sleekening

Verb

sleeken (third-person singular simple present sleekens, present participle sleekening, simple past and past participle sleekened)

1. (ambitransitive) To make or become sleek.
   • Now I have had my gird at thee, my servant, I must tell thee that in sooth it is not all for nothing that thou hast had these months of rest; for verily thou hast grown more of a woman thereby, and hast sleekened and rounded much.1897, William Morris, The Water of the Wondrous Isles