Ground substance is the background material within which all other connective tissue elements are embedded. In ordinary connective tissue, the ground substance consists mainly of water whose major role is to provide a route for communication and transport (by diffusion) between tissues.
Definitions for tiredness. Here are all the possible meanings and translations of the word tiredness. Princeton's WordNet(0.00 / 0 votes)Rate this definition: fatigue, weariness, tiredness(noun) temporary loss of strength and energy resulting from hard physical or mental work. he was hospitalized for extreme fatigue; growing fatigue was apparent from the decline in the execution of their athletic skills; weariness overcame her after twelve hours and she fell asleep.
If you're tired, you should get some rest. If you're tired of being tired, you might need to eat better and exercise more. If you're tired of being told what to do, you should stop asking for advice. Tired can also mean that something is old news, or worn out to the point where people don't want to hear it anymore. Although you still find them funny, your co-workers think your impressions of your favorite cartoon characters are pretty tired. Definitions of tired.