1) Displaying no signs of effort 2) Easy 3) Facile 4) Not showing effort or strain 5) Simple 6) Straightforward 7) Sweat-free 8) Trouble-free 9) Unforced 10) Unproblematic 11) Unstrained 12) Without exertion Found on https://www.crosswordclues.com/clue/effortless
adjective requiring or apparently requiring no effort; `the swallows glided in an effortless way through the busy air` Found on https://www.encyclo.co.uk/local/20974