IPA: /ɪˈrætɪk/
KK: /ɪˈrætɪk/
Not regular or consistent; unpredictable in behavior or performance.
The erratic weather patterns made it difficult to plan the outdoor event.
Comparative: more erratic
Superlative: most erratic
Erratical is derived from 'erraticus' (meaning wandering or straying) in Latin, which comes from 'errare' (meaning to wander or to stray). The word describes something that is not fixed or is wandering in nature.
Think of 'wandering' ('erraticus') to remember that 'erratical' refers to something that is not fixed and tends to stray.