Two words
May be 2 words combined (retro+capitulum) If not obvious, probably incorrect
capitul.um N 2 2 NOM S N
capitul.um N 2 2 VOC S N
capitul.um N 2 2 ACC S N
capitulum, capituli N (2nd) N [EEXBE] Later
chapter/article (in book); religious/cathedral chapter, chapter meeting/house;
little head; piles/hemorrhoids; flower-head/seed-capsule; head of a structure;
retro ADV POS
retro ADV [XXXBX]
backwards, back, to the rear; behind, on the back side; back (time), formerly;
*

Credits:
This, our local install of the popular standby Whitaker's Words, is possible thanks to the resurrection of the venerable project at William Whitaker's Words, where you will also find extensive documentation. The corresponding GitHub repository is where you can submit issues about missing forms and analyses.
This web interface by Walter M. Shandruk.