Tucker trying to understand "pretext?" & ideas for a lesson plan

Does 'pretext' (in the context of our assignments) mean 'a reason for doing something/creating something? 

For example: I had a lesson idea using Brewer's Dictionary of Phrase & Fable. I thought it could be used to help students to find a starting point for a piece of visual art (but could also be used in drama). The symbolism of words and expressions could be discussed, and students would be expected to thoroughly/deeply understand the various meanings of the chosen word or phrase, and to then express it thoughtfully in a piece of art: to communicate the depth of the idea. 

For example: the word Frog can conjure many meanings including the idea of metamorphosis. Frenchmen are sometimes called frogs and there are several reasons for this including their ancient heraldry (3 frogs or toads); the fact that Paris was built on a quagmire and was formerly known as 'Lutetia' (meaning 'mudland'); as well as  the more common idea that the term came from Frenchmen eating frogs legs (Evans, 1993).

In this case, would Brewer's Dictionary of Phrase & Fable be the artefact? And the desire to fully understand and communicate the meaning of the word 'frog' in a personalised way (i.e. reason for art activity), the pretext ?

References

I.Evans. (1993). Brewer's dictionary of phrase and fable. (14th Ed.). London: Cassell Publishers.