IPA: /ʌnˈklæst/
KK: /ʌnˈklæst/
Not fastened or secured with a clasp.
The necklace lay unclasped on the table, waiting to be worn.
Unclasped → It is formed from "un-" (meaning not) and "clasp" (from Old English "claspan", meaning to fasten or grip) and the suffix "-ed" (indicating past tense). The word "unclasped" means not fastened or released from a grip.
Think of something that is 'not fastened' ('un-') — that's why unclasped means it has been released from a grip.