つまり (or 詰（つ）まり) is a word in Japanese that is often used as a 副詞（ふくし） (adverb). It takes a previous statement (said either by the speaker or by someone else) and summarizes it. This translates as ‘in short’, ‘in other words’, and similar expressions in English.
Hamasaki-san didn't come to work without saying anything again? In other words, he ditched work again, didn't he?
Did you really break up with your boyfriend? In other words, that means we don't have to deal with him anymore?
Someone quit again ? In other words, we need to find a new person as soon as possible, right?
comes from verb 詰（つ）まる meaning to become ‘packed’, or ‘condensed’. This means that the literal translation is of つまり
is quite similar to its English interpretation.
You are saying that you were at home playing video games without doing any chores yesterday. Condensed, you were being lazy. (In short)