IPA: //ʌnˈtaɪmliər//
KK: /ʌnˈtaɪmliːər/
Happening at an inappropriate or inconvenient time; occurring too early or too late.
His untimelier arrival caused confusion at the meeting.
Comparative: untimelier
Superlative: untimeliest
Untimelier → It is formed from the prefix 'un-' (meaning not) and 'timely' (from Old English 'timelic', meaning occurring at the right time) and the comparative suffix '-er' (meaning more). The word 'untimelier' means more not occurring at the right time or less timely.
Think of 'not' ('un-') being added to 'timely' to remember that 'untimelier' means something that is more out of time or less appropriate for the moment.
No commonly confused words.