waiting for a call on livestream
Internet slang used by streamers who are waiting for viewers to call in, often via voice chat or similar interactive features.
今夜は凸待ち配信をする予定です。
I plan to do a call-waiting stream tonight.
waiting for an assault from another party
Internet slang, often used in gaming contexts where a player or group is expecting an attack from another party.
敵の凸待ちをして迎え撃つ作戦だ。
It's a strategy of waiting for the enemy's assault and then counterattacking.
From 凸 (とつ, 'convex', used in internet slang to mean 'call' or 'attack') + 待ち (まち, 'waiting'). The exact origin of 凸 for 'call' is uncertain, but it may relate to the shape of a phone icon or the idea of 'poking' someone.