Read the parts:
类语 (lèiyǔ, 'similar words / words by category') +
辞典 (cídiǎn, dictionary) = a dictionary that groups similar words. Mainland sources also use
同义词词典 (tóngyìcí cídiǎn, 'synonym dictionary');
类语辞典 has a slightly more bookish or Taiwan/Japan-flavored ring.
