There are 53 words hidden in the letters of HAPPILY, from 11 two-letter words up to HAPPILY (7 letters). For points, HAPPILY is best at 17.
No other single word uses all 7 letters of HAPPILY. HAPPILY has 7 letters: 2 vowels and 5 consonants, worth 17 points before any board bonuses.
7-letter words 1
5-letter words 9
apply12haply13happy15hippy15lippy12palpi9phial10phyla13pipal9
4-letter words 11
hail7hila7hiya10hyla10pail6palp8paly9pial6pily9pipy11play9
3-letter words 21
ail3alp5hap8hay9hip8hyp11lap5lay6lip5pah8pal5pap7pay8phi8pia5pip7ply8pya8yah9yap8yip8
2-letter words 11
ah5ai2al2ay5ha5hi5la2li2pa4pi4ya5
Words are from our open word list and include some game-only words. Rude words are left out of this page; the unscrambler shows every valid word, lets you add blank tiles and filter by length.