What is meant by abstract ideas?
Presumably, ideas that are thought or imaged, but are not in physical existence at that point of time.
In Latin the word "Abstract" literally means
= "to be pulled away from" (in verb form).
In psychology, when addressing these ideas, we tend to use the label "abstract" on specific thoughts or ideas that might occur to someone that may seem - in most cases - unthought of by any other group or individual.