Semantic change: English bead originally meant "prayer", and acquired its modern sense through the practice of counting prayers with beads.
Most often combinations of etymological mechanisms apply. For example, the German word bitte (please) the German word beten (to pray) and the Dutch word bidden (to pray) are related through sound and meaning to the English word bead.
The combination of sound change and semantic change often creates etymological connections that are impossible to detect by merely looking at the modern word-forms. For instance, English lord comes from Old English hlāf-weard, meaning literally "bread guard". The components of this compound, in turn, yielded modern English loaf and ward.