forces, energy, military strength
勢 centers on dynamic power and momentum: the force or energy that drives action, whether physical, social, or military. It captures the idea of a surge or impetus that pushes things forward.
勢 combines 埶 (a phonetic component associated with planting or setting) with 力 (strength), suggesting the force or momentum needed to establish something. The exact historical development of 埶 is uncertain, but the combination conveys power and impetus.
The top part 埶 looks like a mound of earth being shaped, and the bottom 力 is strength. Picture a powerful surge of energy pushing the earth into place—that force and momentum is 勢.
For セイ, imagine a great wave of energy surging forward as you say 'say!'—like commanding the force to speak its power: say -> セイ.
posture; pose; position; stance; carriage (of the body)
force; vigor; vigour; energy; spirit; life
group (of people, competitors, companies, etc.); contingent; camp; team
influence; power; might; strength; potency; force; energy
general situation; general trend; general tendency; way things are moving; current (of the times); tide (e.g. of public opinion)
crowd of people; great number of people
state of things; state of affairs; situation; conditions; circumstances
attitude; posture; preparedness; readiness
superiority; superior power; predominance; preponderance
posture; position; stance
offensive (movement); aggression
all members; whole army
inferiority (e.g. numerical); inferior position; disadvantage; unfavorable situation; unfavourable situation
power; might; authority; influence
assembling (in full force); muster; lining up; gathering; getting together
condition; situation; prospects
(national) census
strength of a party
actual; real; true
fervour; fervor; vigour; vigor; ardour; ardor; spirit
state of a country (population, resources, etc.); condition of a country; strength of a country
(being on the) defensive