deterior.are V 1 1 PRES ACTIVE INF 0 X
deterior.are V 1 1 PRES PASSIVE IND 2 S Early
deterior.are V 1 1 PRES PASSIVE IMP 2 S
deterioro, deteriorare, deterioravi, deterioratus V (1st) [EXXES] Later uncommon
make worse; deteriorate;
deterioro, deteriorare, deterioravi, deterioratus V (1st) TRANS [EXXFS] Later veryrare
deteriorate, make worse;
Syncope r => v.r
Syncopated perfect often drops the 'v' and contracts vowel
deteriorav.ere V 1 1 PERF ACTIVE IND 3 P
deterioro, deteriorare, deterioravi, deterioratus V (1st) [EXXES] Later uncommon
make worse; deteriorate;
deterioro, deteriorare, deterioravi, deterioratus V (1st) TRANS [EXXFS] Later veryrare
deteriorate, make worse;

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.