Antonyms of adj single-handed

2 senses of single-handed

Sense 1
single-handed, unassisted, unbacked -- (unsupported by other people)

INDIRECT (VIA unsupported) -> supported -- (sustained or maintained by aid (as distinct from physical support); "a club entirely supported by membership dues"; "well-supported allegations")

Sense 2
single-handed -- (without help from others; "a single-handed accomplishment")

INDIRECT (VIA independent) -> dependent -- (relying on or requiring a person or thing for support, supply, or what is needed; "dependent children"; "dependent on moisture")

Similarity of adj single-handed

2 senses of single-handed

Sense 1
single-handed, unassisted, unbacked -- (unsupported by other people)
       => unsupported (vs. supported) -- (not sustained or maintained by nonmaterial aid; "unsupported accusations")

Sense 2
single-handed -- (without help from others; "a single-handed accomplishment")
       => independent (vs. dependent) -- (free from external control and constraint; "an independent mind"; "a series of independent judgments"; "fiercely independent individualism")

Synonyms of adv single-handed

1 sense of single-handed

Sense 1
single-handed, single-handedly -- (without assistance; "I built this house single-handedly")