Adjective spiritless has 3 senses
- spiritless - lacking ardor or vigor or energy; "a spiritless reply to criticism"
Antonyms:  spirited, boisterous, knockabout, con brio, dashing, gallant, ebullient, exuberant, high-spirited, feisty, plucky, spunky, hoyden, hoydenish, tomboyish, impertinent, irreverent, pert, saucy, lively, racy, mettlesome, resilient, snappy, whipping, sprightly, vibrant, vivacious, zestful, yeasty, zesty, barmy
 - spiritless - lacking spirit; "it was a spiritless attempt"
Antonym:  enthusiastic (indirect, via unenthusiastic)
 - compliant, meek, spiritless - evidencing little spirit or courage; overly submissive or compliant; "compliant and anxious to suit his opinions of those of others"; "a fine fiery blast against meek conformity"- Orville Prescott; "she looked meek but had the heart of a lion"; "was submissive and subservient"
Antonym:  domineering (indirect, via submissive)
 
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