heavens, sky, imperial
天 centers on the vast expanse above: the sky, the heavens, and by extension the imperial realm seen as divinely connected to the sky.
sky
angel
genius; prodigy; natural gift
weather
Emperor of Japan
nature; spontaneity
paradise; heaven; Kingdom of Heaven
ceiling
the whole world
weather
heavenly god; heavenly gods
tempura; deep-fried fish and vegetables in a light batter
tengu; red-faced and long-nosed goblin said to reside deep in the mountains
heavenly body; celestial body; astronomical object
heaven and earth; the universe; the world; nature
His Majesty the Emperor
astronomy
being amazed; being horrified; being taken aback
fine weather (i.e. little or no clouds); fair weather; clear weather; clear sky; fair skies
astronomy
bad weather
top; summit; apex; peak
rainy weather
open-air bath; rotenburo; rotemburo
天 is a pictograph of a person with an emphasized head, representing the sky or heavens above. The modern form shows a horizontal line over 大 (person), symbolizing the sky above a person.
The top horizontal line represents the sky, and 大 below is a person with arms outstretched. Together, 天 shows the heavens above a person.
For テン, imagine ten (テン) clouds stretching across the sky: ten -> テン, and the sky is filled with them.