Having been shown the textbook definition of irrational, rather than admit that perhaps you chose your particular vocabulary unwisely, you then proceed to make the claim that one's perspective is sufficient to change said textbook definition, which is another error. Definitions do not change due to circumstance or perception; acting irrationally in a public school is acting irrationally regardless of whether or not one is a parent.
Assuming you wish to continue this long-defeated argument, you'll need to provide some sort of proof that definitions change under such circumstances - something I doubt you'd be capable of doing, simply because it's linguistically impossible. Of course, anything can happen. Maybe you can get millions of English-speaking individuals to suddenly switch definitions of words like 'irrational' based on whether or not you are a parent. If so, I humbly request that you change the words 'ninja' and 'pirate' to 'rattlesnake' and 'pteradactyle', respectively. I'm getting tired of the old internet debate about which is better between the two, and it would be nice to see some webpages designed for moms and dads dealing with the proverbial rattlesnake and pteradactyle fight.
Besides, ninjas and pirates are last year's pink!