To Accompany
To Be Accompanied By, To Go Hand In Hand With
intransitive verb, transitive verb, godan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means accompany, so the verb vocab version is to accompany or to be accompanied by.
This word is both transitive and intransitive. So it works both when bringing someone with you, like 助手を伴って来る (to come with an assistant), or when going along with someone else, like 上司に伴って行く (to go with one's boss). When it's about physically accompanying someone, it's often used together with a movement verb.
伴う is also used figuratively to talk about consequences that tend to go hand in hand with something, like 変化にはリスクが伴う (change comes with risk). In this case, 伴う is usually used by itself.
When you want your friend to accompany you somewhere, you yell "友, NOW!" (ともなう) to command them to get ready to go. You're very pushy when it comes to having your friends accompany you places.
上司に伴って出張に行ってきました。
I accompanied my boss on a business trip.
登山は危険を伴うものです。甘く見てはいけません！
Mountaineering can be dangerous. Do not take it lightly!
はっきり言わせてもらうけど、責任を伴わない自由はただのわがままだよ。
Let me be clear: freedom without responsibility is just selfishness.
技術の進歩に伴って人々は自然環境にだんだん関心がなくなってきた。
Together with the progress of technology, people have grown less and less concerned about the environment.