A list of 35 words by valse.
- hearten appears on 4 other lists
- gladden appears on 3 other lists
- flatten appears on 8 other lists
- smarten appears on 2 other lists
- blacken appears on 4 other lists
- frighten appears on 5 other lists
- lighten appears on 4 other lists
- brighten appears on 5 other lists
- liven appears on just this list
- shorten appears on 1 other list
- heighten appears on 7 other lists
- fatten appears on 3 other lists
- straighten appears on 6 other lists
- redden appears on 5 other lists
- whiten appears on 3 other lists
- dampen appears on 9 other lists
- tighten appears on 2 other lists
- enliven appears on 14 other lists
- awaken appears on 6 other lists
- enlighten appears on 32 other lists
- embolden appears on 13 other lists
- foreshorten appears on 5 other lists
- madden appears on 3 other lists
- sadden appears on 2 other lists
- darken appears on 4 other lists
- fasten appears on 12 other lists
- harden appears on 4 other lists
- soften appears on 12 other lists
- stiffen appears on 3 other lists
- loosen appears on 5 other lists
- weaken appears on 2 other lists
- strengthen appears on 13 other lists
- sweeten appears on 6 other lists
- sicken appears on just this list
- moisten appears on 2 other lists

ruzuzu What a fun list! Apr 15, 2013
mollusque Oops, I saw adjectiven in the list title and didn't read the fine print. Mar 19, 2009
valse I should've just made this list an open one :p ...er, except I wouldn't want all those pesky participles, as sionnach aptly pointed out. Mar 19, 2009
wytukaze Yeah, wrong -en morpheme. Mar 19, 2009
sionnach Hmm. But aren't those participles rather than infinitive forms, mollusquebaugh? Try putting a 'to' in front of them and see where it gets you.
on edit: bigEARS! B-have! Mar 19, 2009
bilby Why is left to me to suggest turducken? Mar 19, 2009
mollusque Bedridden, beholden, browbeaten, crestfallen, downtrodden, forbidden, ghostwritten, godforsaken, heartbroken, interwoven, misbegotten, outspoken . . . Mar 19, 2009
sionnach fasten, harden, soften, stiffen, loosen, weaken, strengthen, sweeten, sicken, Mar 19, 2009
sionnach I find this list at the same time maddening and saddening, as I look out on the darkening sky.
Mar 19, 2009
valse Also, interesting to note the color-related words...blacken, redden and whiten. Neither yellowen nor mauven nor purplen are in use yet. Mar 19, 2009
valse Good points...I'm not sure I want to accept all the prefixed words, but then again, the words enlighten and embolden are certainly well-established and distinctive words. Then enliven and awaken, definitely. Thanks to you both! Mar 19, 2009
wytukaze Ah, enhearten I wouldn't've accepted as a word, but the other three (especially foreshorten) are obvious in relative terms, yeah. Mar 19, 2009
milosrdenstvi you can add prefixes to some of the ones you have...enhearten, foreshorten, enlighten...as well as embolden...I think the en- em- prefix will do well by you. Mar 19, 2009
wytukaze enliven, awaken, quieten? That's all I can think of, though—certainly nothing with 3 syllables or more. Mar 19, 2009
valse Are there no polysyllabic words that can fit in this -en form? Mayhap I found me a linguistical rule :D Mar 19, 2009