To loudly scold and strongly encourage someone — a forceful pep talk intended to spur action or effort.
監督は試合後、選手たちを叱咤激励してさらに練習を重ねさせた。
After the match the coach gave a loud scolding and encouragement, pushing the players to train harder.
社長の叱咤激励でチームは危機を乗り越えた。
The team overcame the crisis thanks to the CEO's stern admonitions and encouragement.
先輩が叱咤激励してくれたおかげで、最後までやり遂げることができた。
Because my senior scolded and encouraged me forcefully, I was able to see it through to the end.