Arecoline \A*re"co*line\, n. Also -lin \-lin\ . [From NL. Areca, a genus of palms bearing betel nut.] An oily liquid substance, {C8H13O2N}, the chief alkaloid of the betel nut, to which the latter owes its anthelmintic action. Syn: arecholine; arecaline; methylarecaidin; methyl N-methyltetrahydronicotinate; 1,2,5,6-tetrahydro-1-methyl-3-pyridinecarboxylic acid methyl ester. [Webster 1913 Suppl.]