stand out

1.  Protrude, project, as in Those reliefs stand out from the building walls. [First half of 1500s]
2.  Be conspicuous, distinctive, or prominent, as in He's so tall that he always stands out in a crowd. [Mid-1800s]
3.  Refuse to comply, remain opposed, as in The one juror is standing out against a guilty verdict. [Late 1500s]

Definition: be conspicuous, prominent
Antonyms: obscure

The verb has 4 meanings:

Meaning #1: be highly noticeable
  Synonyms: leap out, jump out, jump, stick out

Meaning #2: distinguish oneself
  Synonyms: excel, surpass

Meaning #3: steer away from shore, of ships

Meaning #4: be stubborn in resolution or resistance