Wiktionary
vb. to keep
Usage examples of "hang onto".
She needed something solid to hang onto, something warm, something strong, something that could balance the queasy fear coiling through her.
I'd had it in mind to hang onto him and walk him to the door with me, but the moment my hand went out, I knew this was when he would want to shoot me.
FLYING MADRID TOMORROW FOR BARBER BEANO HANG ONTO YOUR HAT LOVE, HARRY.
Sunday morning in Woody Creek and here's McGovern on the mini-tube beside my typewriter, looking and talking almost exactly like he was in those speedy weeks between the Wisconsin and Ohio primaries, when his star was rising so fast that he could barely hang onto it.
There's no real hole to shit through, just a gap in the planks, and you squat on this contraption and hang onto the ship's rails and hope for the best.