Can you give some context for this word? Where did you run across it? I couldn't find an entry for "まつすぐ" in two online Japanese-English dictionaries. My first reaction was to wonder if you really meant to write "まっすぐ" which, of course, would mean straight. The kanji is "真っ直ぐ.
If you put "まつすぐ" into Google Translate, it says the phrase means "just wait" but it's a bad idea to rely on Google Translate.