• 勢いきおい — momentum, energy
• 姿勢しせい — posture, attitude
• 大勢おおぜい — crowd, many people
• 勢力せいりょく — influence, power
• 優勢ゆうせい — superiority, predominance
• 情勢じょうせい — situation, state of affairs

勢 combines the radical 力 (power) with phonetic elements that reflect growth or expansion. It’s often used in political, physical, and social contexts to describe influence, movement, or pressure.

The kun-yomi いきおい is frequently used in everyday speech, especially when talking about momentum, trends, or the “force” behind action or change.

風かぜの 勢いきおいが 強つよくなってきた。
The wind is gaining strength.

チームは その勢いきおいのまま 優勝ゆうしょうした。
The team rode that momentum to victory.

“いきおい” is a commonly used reading for everyday expressions involving force or movement.
“セイ” appears in formal or compound words like “勢力” or “優勢.”
“ジョウ” is a less common reading seen in compounds like “情勢.”