painless
词形变化：
副词: painlessly | 名词: painlessness |
同义词：
effortless | easy | trouble-free | unproblematic | simple | straightforward |
反义词：
painful |
painless
词形变化：
副词: painlessly | 名词: painlessness |
同义词：
effortless | easy | trouble-free | unproblematic | simple | straightforward |
反义词：
painful |