Wooden means made from the material of trees. A wooden spoon, a wooden gate, wooden floors.
The literal sense is plain enough, and English uses it to specify what something is made of, in contrast to metal, plastic or glass. The figurative use is unkind and very common in reviews, since a wooden performance is stiff and lifeless, and a wooden expression gives nothing away. British sport has the wooden spoon, awarded as a joke to whoever finishes last. The material itself is wood, and timber is the building trade's word.
Wooden dates from the 1530s and pushed out an older word, treen, which meant made from a tree. English swapped one ending for another and kept the idea exactly.
Middle English
wode
English
wood
English, today
wooden
Built from
From wood + -en. Dates from 1530s, gradually replaced treen (“made from a tree”), from Middle English treen, from Old English triewen. wood comes from Middle English wode. From Middle English wode, from Old English wudu, widu (“wood, forest, grove; tree; timber”), from Proto-West Germanic widu, from Proto-Germanic widuz (“wood”), from Proto-Indo-European h₁weydʰh₁- (“to separate”). The spelling developed as it did in wool. Cognate with Dutch wede (“wood, twig”), Middle High German wite (“wood”), Danish, Norwegian Bokmål, Norwegian Nynorsk and Swedish ved (“wood”), ovd wið (“wood, timber”), Faroese and Icelandic viður (“wood”), Norwegian Nynorsk ved (“wood, firewood”), vid (“wide, broad”). Further cognates include Irish fiodh (“a wood, tree”), Old Irish fid (“tree”) and Welsh gwŷdd (“trees”), from Proto-Celtic widus (“wood”). Unrelated to Dutch woud (“forest”), German Wald (“forest”) (see English wold).
Etymology from Wiktionary, CC BY-SA