When a text (anything with words, whether it be spoken or written) has a topic or subject that a group of words relate to. If a passage of writing included the words
"heart", "flower", "love", "music", "passion" the semantic field would most likely be considered 'love'. A semantic field of love. Also the lexis may be referred to as "flowery" or even femnine

the thing that you don’t have when you’re phones percentage is over 20