(bound form) boundary; border / (bound form) realm

= + : Joan of Arc wants to leave this world and sets up a rocket launch field in the elevator's bathroom. The field looks like a normal crop field, except that there's a rocket in the middle and that the Joan of Arc marked the boundary with white and red tape.

界 character breakdown

to introduce / to lie between / between / shell / armor

= + 丿 + : Mnemonic symbol: 介 looks like a rocket 🚀. Neanderthal Man (人) and Joan of Arc (ji) are preparing a rocket (介) for its start. Between (介) the layers of the outer shell (介) they are stuffing bananas (丿) and dinosaur bones (丨).
surname Tian
field / farm / CL:片[pian4]

= + : Mother Teresa (ti) wants to plant a field of crosses (田) just inside the anthill's kitchen (an2). She ordered a wooden box (囗) with crosses (十) inside and puts them up one by one.

Characters with 界 as component

Japanese variant of 壘|垒

Words with 界

the Three Worlds (as proposed by Mao Zedong), i.e. the superpowers (USA and USSR), other wealthy countries (UK, France, Japan etc), and the developing countries of Asia, Africa and Latin America
supremum (math.) / least upper bound
lower bound (math.) / world of mortals / (of gods) to descend to the world of mortals
infimum (math.) / greatest lower bound
World Expo / abbr. to 世博[Shi4 bo2]
all over the world / everywhere / in all parts of the world
(math.) infimum; greatest lower bound

Sentences with 界

zhè
tia̅n
shàng
nǎi
shì
shén
xia̅n
jìng
jiè