'sub room' is not a correct part of a sentence in written English.
If you want to use it in a sentence, you could use it as a shortened form of 'substitute room', which would be a room that serves as a substitute or replacement for another room. For example: I was going to have my book club meeting in the living room, but since the sofa was being reupholstered, we moved it to the sub room instead.
In a darkened room, he has built a sub-room into which we cannot quite look through a louvred door and frosted window.
For sub-room temperature magnetic refrigeration applications, gadolinium is the first material known to show a large MCE, since it exhibits a maximum value of magnetic entropy change, ( Delta S_{text{ M}}{ hbox{max} } ), of 5 J/kg K at 294 K under an applied magnetic field of 2 T [1].
Now, with the demand for home spa equipment booming, clients are moving their toilets out to separate sub-rooms and turning their main bath spaces into full-fledged home spas.
I was spotted by an organizer who hurried me down to the sub-room where all my classmates were seated in alphabetical order, ready to walk out and make their families proud.
Arrange furniture into smaller "sub-rooms.
I stayed on the fifth floor in a Sub Pop room, which features a record player and a selection of classic vinyl LPs, including, of course, Nirvana.
In 1940 Hetherington had spent three months in the sub-editors' room at the Glasgow Herald.
It was in 1904 that a 24-year-old Basil Clarke joined the Manchester Guardian's sub-editors' room.
The dervishes congregated in an old pomegranate garden, where I always heard Seyed was buried deep within a shavadoon, a sub-basement room, under which ran a stream.
When I found a basement flat – or rather, the sub-let room of a flat – in Notting Hill, I thought I'd cracked it.
Mystery shrouded the identity of the culprit who slammed the door of the Queen Vic's sub-zero room behind Babe as she was putting the leftovers away, but plenty of residents had a motive for wanting to bump off the malicious old bat.
