thinna-

verb. to fade, *(lit.) become grey

A verb in The Etymologies of the 1930s glossed “fade” derived from ON. thintha- under the root ᴹ√THIN having to do with grey things (Ety/THIN), so perhaps more literally “✱become grey”.

thinna-

verb. to fade, to grow towards evening

The punctuation in The Etymologies is considered incorrect (the full dot after this word should conceivably be a comma)

gwinna-

verb. to fade