keeping close to (verb) buckle down: work very hard
Sinonime: acid, afflictive, aggravating, annoying,
bitter, bothersome,
distasteful, exasperating,
grievous, harassing, humiliating,
irksome, irritating, nettlesome, painful, plaguing, provoking, rankling, unpalatable,
vexatious, vexing
Antonime: cheering,
comforting,
pleasing,
satisfying,
soothing,
wonderful