The anagram of RETROT Is "retort."
You can also spell the shorter words retro, otter, tore, tote, trot, tort, err, rot, tot, or, and to.
If you don't know how to spell interrogative than read this this. I n t e r r o g a t i v e
Those letters will spell therefore.
roster
protect
terror
well you just spelled it, E-X-T-E-R-M-I-N-A-T-O-R
p-o-e-t-r-y
amouret
c o o r d i n a t e
R-O-T-T-E-N like you just did -_-
G-E-O-M-E-T-R-Y
e-n-t-r-o-n-g-e