Historical Innovations

noun a synthetic organic compound used as an insecticide

• DDT, or dichlorodiphenyltrichloroethane, was once widely used as a pesticide but has since been banned in many countries due to its harmful effects on the environment and human health.
• I heard they used to spray DDT all over the fields back in the day to get rid of bugs.
• Don't mess with that stuff, it's like DDT for your brain.
• Her criticism was like DDT to his ego, leaving him feeling completely destroyed.

adjective no longer in use or no longer useful; outdated or outmoded

• The old software system became obsolete after the new update was released.
• Nobody uses CDs anymore, they're practically obsolete.
• Flip phones are so obsolete now, everyone has smartphones.
• His traditional way of thinking is becoming obsolete in today's fast-paced world.

noun a system for transmitting messages or signals to a distant place, especially by means of an electric device consisting essentially of a sending instrument and a distant receiving instrument connected by a conducting wire or other communications channel

• The telegraph was a revolutionary form of communication in the 19th century.
• I sent a telegraph to my friend to let them know I was coming to visit.
• Back in the day, people used to 'telegraph' each other before texting was a thing.
• The sudden silence between them was like a telegraph of their deteriorating relationship.

noun a type of postage stamp issued in Britain in 1840, known for being the world's first adhesive postage stamp

• The Penny Black was the world's first adhesive postage stamp, issued in Great Britain in 1840.
• Do you collect Penny Black stamps? I heard they're quite valuable.
• I found a Penny Black stamp in my grandma's old letters - it's pretty cool!
• Her words were like a Penny Black stamp, leaving a lasting impression on everyone who read them.