IPA: /ˈtɑːrdiɪst/
KK: /ˈtɑrdiɪst/
The latest or slowest in arriving or happening.
She was the tardiest student to arrive at the class today.
Comparative: later
Superlative: tardiest
Tardiest → It is formed from "tardus" (meaning slow or late) in Latin, and the suffix "-est" (meaning the most). The word "tardiest" means the most late or the slowest in arriving.
Think of 'tardus' meaning slow, and remember that 'tardiest' refers to being the most late.