The two tags (Unit-of-measure) and (Dimensional-analysis) seem to be duplicates of one another with the majority of questions appearing under each tag being of the form "How do I convert from one set of units to the other." Indeed if you were to google search either of these phrases, the pages to appear are generally tutorials on how to handle such conversions.
In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their fundamental dimensions (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms vs. grams) and tracking these dimensions as calculations or comparisons are performed. Converting from one dimensional unit to another is often somewhat complex. Dimensional analysis, or more specifically the factor-label method, also known as the unit-factor method, is a widely used technique for performing such conversions using the rules of algebra.
Unfortunately, there appears to be a number of posts with the tag Dimensional-analysis with the intention of interpreting the term more as analysis of the dimension of various subspaces of vector spaces such as this question here. This would largely be due to the lack of tag-wiki information on either tag. After noticing this, I attempted to help rectify the situation by putting a fresh tag-wiki and wiki-excerpt, however due to the lack of activity of the tag am unable to suggest synonyms from the main site. There may be a bit of cleanup needing to be done in order to untag those posts which seemed to use this uncommon second definition.
That is what brings me here. I propose some sort of merging and creation of synonym tags between the two of these and other probable tags such as "unit-conversion", and "metric-system." In doing so, I expect users with related questions will have an easier time finding other posts with already detailed solutions and explanations on how the process works, potentially answering their question before it gets posted, and question answerers can more easily suggest useful links to previously answered questions more readily than if the questions were poorly tagged as pre-algebra or pre-calculus.