Actually, it REALLY is a word. Just looked it up.

paˇ¤seˇ¤o /p¨»ˈseɪoʊ; Sp. p¨»ˈsɛɔ/[pah-sey-oh; Sp. pah-se-aw]
noun, plural -seˇ¤os /-ˈseɪoʊz; Sp. -ˈsɛɔs/[-sey-ohz; Sp. -se-aws]
1.a slow, idle, or leisurely walk or stroll.
2.a public place or path designed for walking; promenade.
3.(esp. in Spanish-speaking countries) a usually tree-lined thoroughfare; avenue.