Green’s Dictionary of Slang

shitty adj.1

also shitey, shitty-ass, shittypants

1. [1920s+] covered in excrement; generally filthy.

2. [1920s+] unpleasant, disgusting; mediocre, second-rate.

3. [1920s+] (US) mean, malicious, nasty.

4. [1920s+] (US) tedious, futile; emotional stressful.

5. [1920s+] (US) unwell, ill.

6. [1960s+] (Aus.) bad-tempered.

7. [1970s] (US) dangerous.

8. [1970s] incompetent.

In derivatives

shittiness (n.) (also shiteyness, shitness)

[1960s+] unpleasantness.

In compounds

shitty-livered (adj.)

[1950s+] (Aus./N.Z.) bad-tempered.

shitty-nosed (adj.)

[1970s] (US) sycophantic and contemptible.

In phrases