捉摸[zhuō mō]
词典fathom：英寻。
词典ascertain：弄清，确定，查明。
fathom; ascertain:
例：不可捉摸
unfathomable;
难以捉摸
difficult ascertain
1. 捉摸
1. fathom：fantasize 幻想 | fathom 捉摸 | feel in one's bones 确信