Bata (බට) or Batayak (බටයක්) - A cigarette. (e.g. Batayak gahamuda? (බටයක් ගහමුද?) means 'Shall we have a smoke?')
Bebe (බෙබේ) - Alcoholic. This could be a shorten form for Bebadda (බේබද්දා).
Dekak Da Gannawa (දෙකක් දා ගන්නවා) - Literally 'to have two shots'. To have a drink. Note that Nethi wenna gahanawa (නැති වෙන්න ගහනවා) refers to getting really drunk till one is unconsious. Wadinna ganahawa (වදින්න ගහනවා) means getting high but not really drunk. Mokuth karamuda (මොකුත් කරමුද?) which literally means 'shall we do something' when used in certain contexts means 'shall we have a drink'.
Duma (දුම) - Literally means 'smoke'. Used to mean anything used to have a smoke (e.g. cigarette, cigar, mal (මල්) etc.). (e.g. Dumak adimuda? (දුමක් අදිමුද?) means 'Shall we have a smoke?')
Kudu (කුඩු) - Heroin or other similar narcotics
Mala (මල) or Suusthiya (සුස්තිය) - Roll of Ganja (Cannabis or pot) for smoking or the ingredients used to prepare those. Relatively new term Mala (මල) is preferred over Suusthiya (සුස්තිය) in most social circles.
Netum Thel (නැටුම් තෙල්) - Literally 'Dancing Oil'. Bit outdated but rather sarcastic term referring to any kind of hard liquor.
There are many terms to refer to illicit or homemade liquor which includes Kasippu (කසිප්පු) (this is the most common and accepted name), 'Heli Arrakku' (හැලි අරක්කු) (archaic term means, Pot-Liquor), 'Kashiya' (කෂියා) (which is a pet name derived from more mainstream term Kasippu), 'Vel Beer' (වෙල් බියර්) (means, beer of the paddy field), 'Katukambi' (කටු කම්බි) (means, barbed wire) 'Suduwa' (සුදුවා) (means, the white substance) depending on locality.