Hi Jadzia,
This was my LOI, it's
It's a 5 letter word meaning 'A stretch or "extent" of space and time' and is also a homophone (sort of) of a "caterpillar" as in the industrial earthmover you see on building sites.
Your letters are correct but the 'I' from 13a is an extra letter and goes between the R and A, so it's ?RIAC?