Two words
May be 2 words combined (retro+decima) If not obvious, probably incorrect
decim.a NUM 2 0 NOM S F ORD
decim.a NUM 2 0 VOC S F ORD
decim.a NUM 2 0 ABL S F ORD
decim.a NUM 2 0 NOM P N ORD
decim.a NUM 2 0 VOC P N ORD
decim.a NUM 2 0 ACC P N ORD
decem, decimus -a -um, deni -ae -a, decie (n)s NUM [XXXBO]
10th - (ORD, 'in series'); (a/the) 10th (part) (fract w/pars?);
decim.a N 1 1 NOM S F
decim.a N 1 1 VOC S F
decim.a N 1 1 ABL S F
decima, decimae N (1st) F [XLXDO] lesser
tithe; tenth part; (offering/tax/largesse); tax/right to collect 10%; 10th hour
decim.a V 1 1 PRES ACTIVE IMP 2 S
decimo, decimare, decimavi, decimatus V (1st) TRANS [XWXDO] lesser
choose by lot every tenth man (for punishment); make tithe offering (to a god);
retro ADV POS
retro ADV [XXXBX]
backwards, back, to the rear; behind, on the back side; back (time), formerly;


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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.