The English language is rich because it isn't purely English. Emerson called it "the sea which receives tributaries from every region under heaven". It has taken about 2000 years to evolve.
The Kelts, Jutes, Angles, Saxons, Greeks, Romans, Danes, Normans, Dutch, Germans, French, Spanish, Italians, Indians, American Indians, Africans; to name just a few, have all made major contributions.
Shakespeare's word contributions include about 1,700 words, among them the following: assassinate, auspicious, barefaced, bump, castigate, countless, critical, dwindle, gnarled, hurry, impartial, lapse, laughable, leapfrog, lonely, misplaced, and monumental.
Science has contributed thousands of new words to the English language and here are just a few of them from over the years: magnetism (1616), telescope (1619), gravity (1642), electricity (1646), microscope (1656), botany (1696), zoology (1726), oxygen (1789), atom (1801) evolution (1832), bacterium (1847), pasteurize (1881), hormone (1904), vitamin (1905), and penicillin (1928).
Some war words include these from World War I: binge, camouflage, cushy, scrounge, umpteen, and zoom.
From World War II, we have: blackout, blitz, bulldozer, jeep, and wishful thinking.