opener

opener /ˈoʊpənɚ/ noun
plural openers
opener
/ˈoʊpənɚ/
noun
plural openers
Britannica Dictionary definition of OPENER
[count]
1 
: a tool, device, or machine that is used to open something — see also can opener, eye-opener, letter opener
2 
: the first game, performance, etc., in a series

for openers

informal
: as the first thing to be thought about or said : to begin with