Synonyms for Sluggish (same or very similar meaning)
WordNet sense 1 (with little movement; very slow):
sulky
WordNet sense 2 (not moving quickly; taking a comparatively long time):
slow
WordNet sense 3 ((of business) not active or brisk):
dull
WordNet sense 4 (lacking activity; lying idle or unused):
inactive
WordNet sense 5 (slow and apathetic):
inert, soggy, torpid
From the ODE community, based on WordNet
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