ADJ in n
The 'slow' groupThese adjectives indicate that someone does something quickly or slowly, or that something happens quickly or slowly.
The preposition in is followed by an '-ing' clause.
Success was not long in coming.
They were very quick in spotting that this child was in potential danger, being alone near water and so young.
Mr Swift denied police had been extremely slow in responding to the initial complaints.
The adjective long is also used in the phrase long in the making.
long quick slow tardy
Marie-Antoinette chose a very special fabric, very long in the making, and while she was waiting for it, a simple blue silk was used in it place.