• WordNet 3.6
    • adj rueful feeling or expressing pain or sorrow for sins or offenses
    • ***
Webster's Revised Unabridged Dictionary
    • Rueful Causing one to rue or lament; woeful; mournful; sorrowful.
    • Rueful Expressing sorrow. "Rueful faces.""Two rueful figures, with long black cloaks."
    • ***
Century Dictionary and Cyclopedia
    • rueful Full of pity or compassion; pitying.
    • rueful Worthy of pity or sorrow; lamentable; pitiable; deplorable; sorry.
    • rueful Expressive of regret, sorrow, or misfortune; mournful; sad; melancholy; lugubrious.
    • rueful Synonyms Doleful, lugubrious, regretful.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Rueful sorrowful: piteous: deplorable: mournful: melancholy
    • ***


Chambers's Twentieth Century Dictionary
A.S. hreówan, to be sorry for—hreów, sorrow; Ger. reue, Old High Ger. hriuwa, mourning.


In literature:

Louie scrambled to his feet, a rueful grin on his face.
"Eight Keys to Eden" by Mark Irvin Clifton
Doggie, who was beginning to acquire a sense of rueful humour, smiled and was appeased.
"The Rough Road" by William John Locke
Dripping with rain, and with a rueful aspect, I prefer my request for a lodging.
"A Tramp's Wallet stored by an English goldsmith during his wanderings in Germany and France" by William Duthie
For a moment Tom could be heard muttering rueful exclamations as he caressed his bruises.
"The Radio Boys with the Revenue Guards" by Gerald Breckenridge
She regarded them with rueful consternation.
"The Madcap of the School" by Angela Brazil
The driver swore softly and crossed himself devoutly before he fell to a rueful study of the roof of the landau.
"Captain Dieppe" by Anthony Hope
The trio looked at one another with rueful humour.
"Ghetto Comedies" by Israel Zangwill
There was a pause, and Lady Crawleigh, with a rueful shrug, turned away to speak to Gaymer.
"The Education of Eric Lane" by Stephen McKenna
He looked, indeed, so rueful, and at the same time so wrathful, that Asgill laughed aloud.
"The Wild Geese" by Stanley John Weyman
Then he turned to his friend with a rueful laugh.
"Blake's Burden" by Harold Bindloss

In poetry:

To-day the world's heart feels anew
The vernal thrill,
And thine beneath the rueful yew
Is wintry chill.
""When Birds were Songless"" by William Watson
Therewithal spake King Siward
From rueful heart unfain:
“Ne’er saw I two King’s children erst
Such piteous ending gain.
"Hafbur And Signy" by William Morris
Hawk or shrike has done this deed
Of downy feathers: rueful sight!
Sweet sentimentalist, invite
Your bosom's Power to intercede.
"Whimper Of Sympathy" by George Meredith
Rueful, most vexed, that tender skin
Should accept so fell a wound,
He stamped and cracked stalks to the ground
Which had caused his dear girl pain.
"Bucolics" by Sylvia Plath
And many times has Autumn, on her harvest way,
Gathered again into the earth leaf, fruit, and spray;
Here many times dwelt rueful as she dwells to-day,
The while she reaps.
"Fulfilment" by Cale Young Rice
MISTY his face, and rueful to behold;
His eyes like dimly shining stars were seen:
And cloudy vestments did his form enfold,
Like blue smoke curling in the moonlight sheen.
"Fog" by Charlotte Dacre

In news:

I smiled – a sad and rueful smile – as I read the whole thing.
Hastings made several frank, rueful comments about Netflix's ( NFLX ) mistakes at the UBS Media conference in New York on Tuesday.
Scottish band Frightened Rabbit combines rueful lyrics with grand, uplifting folk-pop arrangements.
Ah, spring and its rueful , roadside reminder of the cycle of life here Commentary Dr Henry F Smith Jr. Saturday, November 24, 2012.
INTERVIEW- Rueful Rufus: Wainwright savors life's battles.
Loft Parties, Cab Rides, Late-Night Fights and Rueful Reassessments: It Must Be New Year's Eve.
This first feature by character actor/theater director Terry Kinney addresses, once again, America's apparent surfeit of sweet- souled losers and eccentrics, replete with rueful indie muzak.
The Hüsker Dü/Sugar vet drops a blast of hook-chiseled guitar noise with rueful lyrics that lead to a refrain of "Can I try to make it up to you somehow".
The cast and creatives of Golden Age took time out from a promotional photo shoot to chat about the rueful new backstage comedy, the world of opera and the work of playwright Terrence McNally.
The memory recently drew a rueful laugh from the once-active sisters, who in recent years have had trouble simply walking.