adv. 一时不知怎么说地；哑口无言地

[ adv ]
without speaking
<adv.all>
he stood up soundlessly and speechlessly and glided across the hallway and through a door

Speechless \Speech"less\, a.
1. Destitute or deprived of the faculty of speech.

2. Not speaking for a time; dumb; mute; silent.

Speechless with wonder, and half dead with fear.
--Addison.
※ -- {Speech"less*ly}, adv. --
{Speech"less*ness}, n.