Scioly.org

S: Pilgrimage
1. Travel
2. People
3. Ethnic Group
4. Social Group
5. Social Sciences
E: Discipline (Specialism)

S: Discipline (specialism)
1. Liberal arts education
2. Music
3. Deafness
4. Toluene
E: Trinitrotoluene

...that's TNT, by the way.

So THAT'S what it means!
S: Trinitrotoluene
1. Reagent
2. Solvent
3. Solution
4. Chemistry
5. Outline of Physical Science
E: Phenomenon

S: Phenomenon
1. Moon
2. Tide
3. Red tide
4. Phytoplankton
E: Mineral

S: Mineral
1. Inorganic Compound
2. Carbon
3. Atomic Number
4. Proton
5. Subatomic Particle
E: Atom

S: Atom
1. Antimatter
2. Observable universe
3. Quasar
4. Wormhole
E: Many-worlds interpretation

S: Many-Worlds Interpretation
1. Interpretations of Quantum Mechanics
2. Quantum Mechanics
3. Action (Physics)
4. Dynamics (Mechanics)
5. List of Academic Disciplines
E: Education

S: Education
1. Profession
2. Dentistry
3. Human mouth
4. Frown
E: Concentration*

*frown linked to the wrong concentration; this is the chemistry type, oddly.

S: Concentration
1. Normality (Chemistry)
2. Molar Concentration
3. Amount of Substance
4. Quantity
5. Property (Phiolosophy)
E: Modern History

S: Modern history
1. Age of Exploration
2. Astrolabe
3. Star chart
4. Astrology
E: Zodiac