Wiktionary
vb. 1 (context idiomatic English) to add something extra to something to make it appear more substantial 2 (context idiomatic slang English) to sleep or go to bed
Usage examples of "pad out".
You can be a satisfied customer and help me wheedle another pad out of the traders in return for this drawing of them.
Gunnery Sergeant Jin, the dark, broad Korean platoon sergeant of Third Platoon, had a pad out and was paging slowly through something on it.
She had thrown off her jacket and Wellingtons and sat on a bench in long underwear just like the other pilots wore, putting on extra socks to pad out the boots of her flying kit, which were not as stretchy as the rest of the outfit.
Fen realized why she had to pry the pad out of Gibb's shaking hands.
Shacklar slipped a small leather-bound pad out of his pocket and flipped it open.
Rather they dozed, rising at intervals to pad out into the darkness where Sander believed they were making rounds of the camp.