그저 is a common word similar to "just", "only / solely", or "always / nothing but" depending on the context. - 그는 하루 종일 그저 잠만 자고 있다: He is just sleeping all day long. - 그녀는 그저 웃기만 했다: She only smiled saying nothing. - 비가 그저 내리고 있다: It is raining with no end. - 그저 바라보기만 하여도: Even if I just look at [her/him/you/?].. If you go deeper, there are more subtle usages too. - 요새는 그저 그렇습니다: These days it is so so (nothing remarkable to mention). - 이 영화는 그저 그래: This movie is just so so. - 그저 한번 해 본 말이다: I was just saying it (without particular intent). - 내 그저 그럴 줄 알았지: I knew it would turn out like this (그저 = no wonder / no surprise) By the way, 그저께 (the day before yesterday) is shortened to 그제, not 그저. 그죠 is short for 그렇죠(isn't it (so)?), and is distinct in pronunciation and intonation.

I think that it means the day before yesterday 그저게 is a longer term. If your listining is off you could be hearing 그죠. I don't think I have seen 그저 by itself, but always with something else like 그저 바라볼 수있어 I'm not a native speaker so I would ask a native for a more definate answer.

공짜는 '거저'입니다. 다른 단어입니다.

'공짜로'의 뜻도 있어요.