open·er 
/ˈoʊpənɚ/ noun
plural open·ers /ˈoʊpənɚ/ noun [count] 1 : a tool, device, or machine that is used to open something
▪ a bottle opener ▪ a garage door opener — see also can opener, eye-opener, letter opener 2 : the first game, performance, etc., in a series
▪ This game will be the season opener [=the first game of the season] for both teams. ▪ The album's opener is a slow love song. ▪ the meal's delicious opener [=starter]
▪ a bottle opener ▪ a garage door opener — see also can opener, eye-opener, letter opener
▪ This game will be the season opener [=the first game of the season] for both teams. ▪ The album's opener is a slow love song. ▪ the meal's delicious opener [=starter]
for openers
informal : as the first thing to be thought about or said : to begin with
▪ She began by asking what we'd done with her money. And that was just for openers! ▪ (chiefly US) “What didn't you like about my poem?” “Well, for openers [=for starters], I hated the title.”
▪ She began by asking what we'd done with her money. And that was just for openers! ▪ (chiefly US) “What didn't you like about my poem?” “Well, for openers [=for starters], I hated the title.”
