adj. Function: adjective
1
Synonyms: HARD 6, arduous, difficult, effortful, formidable, laborious, severe, strenuous, toilsome, tough
2
Synonyms: ASSIDUOUS , diligent, industrious, sedulous
adj. Function: adjective
1
Synonyms: HARD 6, arduous, difficult, effortful, formidable, laborious, severe, strenuous, toilsome, tough
2
Synonyms: ASSIDUOUS , diligent, industrious, sedulous
Merriam Webster. Collegiate thesaurus English dictionary. Английский энциклопедический толковый словарь тезауруса. 2012