I will now put each suggestion in an answer to this question. Feel free to vote on each answer
human and human-skills synonym of physiology
rape synonym of sexual-abuse
fluoride synonym of fluoridation
cost synonym of price
congress synonym of united-states
beer synonym of alcohol
cigarettes and smoking and perhaps nicotine and/or tobacco (not sure which should be the main tag)
programming-productivity synonym of productivity
fitness synonym of exercise
hackers synonym of hacking
vehicle synonym of cars
hollywood synonym of movies
We have medications and drugs should they be merged? We also have recreational-drugs and pharmaceutical
We have money and currency should they be merged?
we have heart-attack, maybe we can make a more generic cardiology tag?
cell-phone and mobile-phones seem like they are half merged. They are listed on the tag synonym page with pending (1) next to it.
I question the value of the following tags: time, causality (seems too much like a meta tag to me), force, lifestyle, networks
I am also questioning the need for both teeth and dentistry.
Feel free to disagree, discuss and comment