The word "Allective" is spelled with two L's despite being pronounced with one. The IPA phonetic transcription for this word is /əˈlɛktɪv/, with the stress on the second syllable. The spelling of "Allective" follows a common English spelling rule where a vowel before "l" is often doubled in a one-syllable word or in the stressed syllable of a multi-syllable word. This rule is important to remember when spelling similar words like "collective" and "selective".
Alluring.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.