What is a computer program?
It is a set of instructions, to be obeyed by a computer. The instructions are mostly arranged in sequence, but selection and repetition are other essential compositional structures.
In looking for a Gaelic term for "computer program", I ask myself what else is like it? What else consists of a series of instructions to be followed? The best I can come up with is a recipe, or a prescription. With the recipe analogy, the recipe is the program, the cook is the computer, the person originating the recipe is the computer programmer.
The Gaelic for "recipe" is "oideas". I think this is quite suitable for a computer program. The most common meaning of "oideas" is "training". And when you supply a computer with a program, you are indeed training it, or programming it, so that it now can perform the task elaborated in the program. Moreover, in Dwelly's Gaelic dictionary, under a cross-reference to "oideachd", we find the meaning "occult science", which I like to think captures one view of computers and programming!
More importantly, we can construct a very satisfactory terminological field around "oideas" meaning "program". And of course "oideas" itself may be expanded to "ríomh-oideas" in any case where the context is not clearly established as computation. Derived terms may include:
"Clár" (FR 296: clár, ríomhchlár) is an unsuitable term for "computer program". Not only is it semantically useless — its basic meaning is a wooden board, and by extension, a smooth flat surface — but worse, there are many computing artifacts which are much more "clár"-like than a program is: desktop, keyboard, screen, disc, menu, etc. In Scotland, "clár" is used for some of these, while the word used for "program" is "prògram". In Ireland, I would regard "prógram" as an acceptable second choice to "oideas" and greatly preferable to "clár".
We might ask, analogously, whether "clár teilifíse" is more suggestive of "television programme" or of "television screen". I would give the same answer as would the Scottish Gaels.