tedious vs tiresome

tedious and tiresome both are adjectives.

Word	Noun	Adjective	Verb	Adverb
tedious	No	Yes	No	No
tiresome	No	Yes	No	No

As adjectives, tedious and tiresome are synonyms defined as:

tedious and tiresome: so lacking in interest as to cause mental weariness

Other synonyms of tedious include boring, deadening, dull, ho-hum, irksome, slow, wearisome.

tedious (adjective)	tiresome (adjective)
using or containing too many words	so lacking in interest as to cause mental weariness
so lacking in interest as to cause mental weariness