alkalithermophilic UK /ˌæl.kə.laɪˌθɜː.məʊˈfɪl.ɪk/US /ˌæl.kə.laɪˌθɝː.məˈfɪl.ɪk/ adjective1 •Thriving in both highly alkaline and high-temperature environments. formsmore alkalithermophilic · most alkalithermophilic