A noun for a “track” appearing in a 1968 essay, which Tolkien described as follows:

Both Quenya and Lindarin [Telerin] also possessed a word ratta, which might be a derivative (by lengthening the medial consonant, a frequent device in Primitive Eldarin) from either *rattha [from RATH “climb”] or *ratta from the stem RAT [“find a way”] and in senses seems to be a blend of both. It meant ‘a track’; though often applied to ways known to mountaineers, to passes in the mountains and the climbing ways to them, it was not confined to ascents. It could be used of tracks across a marshland, or trails (blazed or sometimes marked by guide-stones) in forests (NM/363).

Thus Q./T. ratta seems to have applied to any “track” through the wilderness (not necessarily one that climbs) as a derivative of √RAT “find a way”, as opposed to S. rath “(climbing) track or street” that was more influenced by √RATH “climb”; see that entry for discussion.