Unpredictable

How to spell unpredictable

13 letters · 5 syllables

How to pronounce unpredictable

Say the part in capitals loudest.

What does unpredictable mean?

1. adjectiveNot able to be foreseen or relied upon to behave in a consistent way.

Unpredictable in a sentence

• The autumn weather here is famously unpredictable.

• His moods were so unpredictable that colleagues trod carefully around him.

Where does unpredictable come from?

Language of origin: Latin

This word builds on the Latin verb dicere, meaning 'to say' or 'to tell', whose past participle dictus gives English a whole family of related words. By joining the prefix prae-, meaning 'before', Latin formed praedicere, 'to say beforehand', which is the literal source of 'predict': to foretell something before it happens. English took 'predict' into use in the early 1600s, then added the productive suffix -able, meaning 'capable of being', to make 'predictable'. The negative prefix un-, a thoroughly native English element meaning 'not', completed the journey to 'unpredictable', describing what cannot be foretold. The same dicere root quietly sits inside 'dictionary', 'dictate', and 'verdict', and the cluster of small prefixes and suffixes is exactly why the word looks longer and trickier to spell than it really is.

How the word is built

• un- (not)
• pre- (before)
• dict (from dicere: to say)
• -able (capable of)