The word "sens" has different meanings. 1/ Like you said we have les cinq sens: ouie, vue, toucher, goût, odorat (hearing, sight, touch, taste, smell) 2/ A direction, orientation. That's the meaning used in "sens interdit", it means you're not allowed to take this road in this specific direction. 3/ The meaning of a word, for example you could have asked "Quel est le sens de ce mot ?" (what's the meaning of this word?) 4/ The meaning of something (e.g. the meaning of life: "le sens de la vie") There are probably some other meanings, but I think these four are the main ones.