םמד from left to right.
A prim root to be dumb; by implication, to be astonished, to stop; also to perish:
KJV -- cease, to be cut down (off), forbear, hold peace, quietself, rest, be silent, keep (put to) silence, be (stand) still, tarry, wait.
The literal interpetation to stand still appears to be the meaning rather than the figurative interpetation to be silent:
"In I Samuel 14:9 the concept of "waiting" or "standing still" appears. This seems to be the meaning when Joshua askes the Lord to make the sun "stand still" and the moon "stop" so he could pursue the Amorites. Those interpreters who explain this miracle in terms of the silencing of the sun's heat have a more difficult time, especially in view of the parallelism with the moon."