Technically, if you expose film using a meter setting different than the ISO speed of the film, you are using an "Exposure Index" or EI rather than the ISO or box speed.
If you meter after setting an EI on your meter which is higher than the film's ISO setting, you end up exposing the film to less light. Many who are forced to deal with low light levels resort to doing this.
If you meter after setting an EI on your meter which is lower than the film's ISO setting, you end up exposing the film to more light.
Sometimes, film becomes less sensitive to light due to age and other factors. In response to that, people sometimes increase the amount of light reaching the film by setting a lower EI on the meter.
They also may elect to modify the contrast of the film by adjusting development. That is where "pushing" and "pulling" come in.
A "push" development is one where the development time is extended. Its main benefit is that it increases the contrast of images that have too little contrast to start with. As it has the effect of increasing contrast, it tends to make exposed film look slightly better when it has received less than ideal exposure.
A "pull" development is one where the development time is decreased. Its main benefit is that it decreases the contrast of images that have too much contrast to start with. As it may also involve a slight decease in film sensitivity, it is often used with a slight increase in exposure.
Technically, the phrase "push" doesn't actually refer to exposure, but because a lot of people combine under-exposure with increased ("pushed") development, many use "push" to refer to both underexposure and increased development.
For 10 year old expired amateur market colour film, I wouldn't normally adjust development. The normal, ISO or box speed would probably be appropriate for exposure, but as colour negative film is very tolerant of over-exposure, I might consider increasing exposure of the film by a stop by setting my meter to an EI that is one stop lower - 100 rather than 200 in the situation you describe.
For clarity: changing the speed setting on your meter doesn't constitute pushing or pulling film - you need a corresponding change in development as well before you apply those terms.
By changing the setting on the meter, you are simply increasing or decreasing the exposure.