Iron-deficiency anemia can cause fatigue (tiredness), shortness of breath, chest pain, and other symptoms. Severe iron-deficiency anemia can lead to heart problems, infections, problems with growth and development in children, and other complications.
Semantics is the study of meaning. It is a wide subject within the general study of language. An understanding of semantics is essential to the study of language acquisition (how language users acquire a sense of meaning, as speakers and writers, listeners and readers) and of language change (how meanings alter over time).
subject definition, subject meaning | English dictionary. subject. a the predominant theme or topic, as of a book, discussion, etc. 4 a person or thing that undergoes experiment, analysis, treatment, etc. 5 a person who lives under the rule of a monarch, government, etc.