Try using the VLOOKUP function. On your descriptions sheet, add a column before the descriptions so it's like this (the "." are there for spacing):

.....A.......................B
1 BASIC......This is a Basic Description
2 SS..........This is a SS Description
3 FL...........This is a FL Description
.
.
8 SRC.........This is a SRC Description

Then, on your main sheet, use this formula to pull out the 'BASIC', 'SS', etc. from after the hyphen and search for that text in the lookup array on the Description Sheet:

=VLOOKUP(RIGHT(A1,LEN(A1)-FIND("-",A1)),Sheet2!A1:B8,2,0)

This assumes that all part numbers are in the format "randomtext-YOURCODE". If there is data formatted with multiple hyphens, or such that it is "randomtext-randomtextYOURCODE" then this won't work properly.