Answer:
Improve
It is difficult to know which word you mean without seeing it in hieroglyphs. If you mean the plant called yam, it was not grown in Egypt in ancient times.
A few possible words you might mean are written in hieroglyphs as:
iAm..................to offer, make an offering
iAm..................to bind a sacrificial animal
ym....................the sea
im......................in, with, by means of, from, out of, as, when, together with
You may notice your word is followed by a determinative sign that will help establish the meaning (ym - the sea - is generally followed by three zigzag "water" signs).