Solutions :

3-letter words (1 point): 37

AID; AIL; AUA; AUE; BED; BEE; BEL; BID; DAE; DEB; DEE; DEI; DEL; DEX; DIB; DIE; DIN; DUE; DUI; EAU; EEL; ELL; IDE; ILL; LED; LEE; LEI; LEU; LEX; LID; LIE; LIN; LUD; NID; NIE; NIL; NIX.

4-letter words (1 point): 32

AIDE; BEDE; BEDU; BEIN; BELL; BIDE; BIDI; DEBE; DEIL; DELI; DELL; DIEB; DIEL; DILL; DUEL; DULL; EIDE; EXED; IBEX; IDEA; IDEE; ILEX; ILIA; LEUD; LIED; LIEU; LUDE; NIDE; NIDI; NIED; NILL; NIXE.

5-letter words (2 points): 8

ADIEU; BEEDI; DILLI; DULIA; EDILE; ELIDE; EXILE; NIXED.

6-letter words (3 points): 9

AEDILE; AUDILE; BEDUIN; DUELLI; EXILED; ILLUDE; LILIED; NIELLI; NILLED.

7-letter word (7 points): 1

BELLIED.