vṛthā

fruitless — Madhya 2.40

in vain — SB 3.30.12

unnecessarily — SB 6.2.2, SB 9.15.38, SB 10.4.12, Antya 14.111

useless — Ādi 4.118

uselessly — SB 3.5.14, Madhya 24.128, Antya 16.136

with no purpose — Madhya 2.45

without any good result — SB 8.21.33

without purpose — SB 1.7.51

useless talk — Antya 2.125