1.
If something stands out, it is very noticeable.
Every tree, wall and fence stood out against dazzling white fields...
PHRASAL VERB: V P
2.
If something stands out, it is much better or much more important than other things of the same kind.
He played the violin, and he stood out from all the other musicians...
PHRASAL VERB: V P from n
3.
If something stands out from a surface, it rises up from it.
His tendons stood out like rope beneath his skin...
= stick out
PHRASAL VERB: V P