Antonyms of adj wimpish

1 sense of wimpish

Sense 1
wimpish, wimpy -- (weak and ineffectual)

INDIRECT (VIA forceless) -> forceful -- (characterized by or full of force or strength (often but not necessarily physical); "a forceful speaker"; "a forceful personality"; "forceful measures"; "a forceful plan for peace")

Similarity of adj wimpish

1 sense of wimpish

Sense 1
wimpish, wimpy -- (weak and ineffectual)
       => forceless (vs. forceful), unforceful -- (lacking force; feeble; "a forceless argument")