rem acu tango
From rem the accusative of rēs (“thing, matter, issue”) + acū (“with a needle”), the ablative of acus (“a needle”) + tangō (“I touch”). Literally meaning "I touch the issue with a needle, "I touch the matter with a needle" or "I touch it with a needle".
- Usually used in the active perfect second person singular form rem acū tetigistī (“"you have touched the matter with a needle"; you have hit the nail on the head”), the word rem is sometimes omitted as in acū tetigistī (“"you have touched with a needle"- you have hit the nail on the head”). It is also used in the third person; rem acū tetigit (“"he touched it with a needle"- he has hit the nail on the head”).