Verb (5-dan, る, intransitive)
1. to have a cramp; to twitch; to spasm
2. to stiffen (of a face, expression); to freeze; to grow tight (e.g. of a voice)
だけど彼の笑顔は少し引きつっている。But his smile is a little stiff.
3. to shrink (of skin, due to a scar); to tauten