1.Definition: (used of physical stimuli) serving to stimulate or excite

Related Adjective(s):irritative

2.Definition: causing irritation or annoyance

"An irritating delay"

Related Adjective(s):annoying, bothersome, galling, nettlesome, pesky, pestering, pestiferous, plaguey, plaguy, teasing, vexatious, vexing

3.Definition: causing physical discomfort

"Bites of black flies are more than irritating; they can be very painful"

Related Adjective(s):painful