This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The modern form combines 虫 (insect) with 矍, but the original semantic and phonetic roles are unclear.
The insect radical 虫 beside the complex 矍 suggests some kind of insect or bug, but the exact meaning is unclear.
For キャク, imagine a strange insect making a sharp 'kyak' sound as it scurries away: kyak -> キャク.