1. there's no (other) way
こうするより仕方がない。There's no other way but to do this.
2. cannot be helped; unavoidable; inevitable; (there's) nothing one can do; having no choice
いいのよ、仕方がないわ。It's fine, there's nothing that can be done.
3. it's no use (doing); pointless; useless; no good; insufficient; not enough
oft. as 〜ても仕方がない
あとのことを考えても仕方がない。It is no use thinking about what comes after.
4. hopeless (person); annoying; troublesome; awful
5. cannot stand it; unbearable; cannot help (doing, feeling); dying (to do)
as 〜て仕方がない or 〜で仕方がない
それが不安で仕方がない。I cannot help feeling anxious about that.