Verb stem + -(으)러 simply means "in order to do..."^^' 만나다(to meet, see) 만나 + -(으)러 ☞ 만나러 ☞ in order to meet 먹다(to eat) 먹 + -(으)러 ☞ 먹으러(먹 has the final consonant ㄱ, so 으러 not 러) 오늘 만나러 갔어요 ☞ I went to meet him/her today \^o^/

I always remember the structure (으)-러 가다 / (으)-러 오다 as "to go/come ____" 오늘 만나러 갔어요 (Today, I went to meet _____.) Compared to 오늘 ___ 만나요 or 오늘 ___가요, the usage of (으)-러 가요 has an intention to go do something rather than stating it as it is without any meaning behind it.