'ró-' is a prefix you'll come across quite a bit.
You should also know about 'an-', which mean 'very' when used with adjectives and 'great' when used with nouns. It also triggers lenition. To give you an example of its use, if you wanted to say "you're a great man!" to somebody, you'd say "an-fhear!"
You can tell whether it's this prefix or the definite article by the stress pattern. In most dialects of Irish (Munster Irish being the exception), stress is on the first syllable of the word. Thus, in 'an fear', the stress is on 'fear', but in 'an-fhear', the stress is on 'an-'.
A village can be too small - too small to justify opening a shop there, for example, or too small to justify the bus taking a detour from the main road to stop there.
And nowadays, building 10 houses together wouldn't count as a village, even though there are probably some old villages with as few as 10 houses.