seltau lujvo

x1 is the modifying part of binary metaphor x2 with modified part/modificand x3 giving meaning x4 in usage/instance x5

In both English and Lojban, the word seltau is the usual way to refer to the left word in a tanru, whereas tertau refers to the right word in the tanru.

In definition:

co'au'e (exp!)
trivial selbri inversion: does not invert tanru (seltau first/left, tertau second/right).
coi'o'e (exp!)
asks the listener to provide a word matching the preceding description being the seltau
ke'e'ai
Attaches all of the following words to the next explicitly mentioned sumti as seltau of that sumti or selbri which is explicitly marked with "cu" (under left-grouping by default).
ta'u'i (exp!)
Copy and paste the overall seltau of immediately preceding sumti at this location.

In notes:

dornilteikeznulfau
f1 = r1 = x1 (event; perhaps: spacetime coordinates) is an equinox for season x2 at location/of or for celestial body/object d3 = x3 with respect to orbit/sun x4.
labyska
x1 is lightly colored with color x2 [ka]
pavmombesy'utka
x1 is path-connected to x2 via the male-only first-born progeny/primogeniture relation; x1 is the first-born son of the first-born son of ... the first-born son of x2, connected by a graph-path passing through intermediate relations/steps (successive first-born sons) x3 (ce'o; ordered list).
pavmompazy'utka
x1 is path-connected to x2 via the (non-gendered/absolute) first-born progeny/primogeniture relation; x1 is the first-born offspring of the first-born offspring of ... the first-born offspring of x2, connected by a graph-path passing through intermediate relations/steps (successive first-born offspring) x3 (ce'o; ordered list), "first" being according to ordering rule x4 (default, as used in this definition: chronological order of birth; restrictions on legitimacy etc. may also be included here).
pavmomtixy'utka
x1 is path-connected to x2 via the female-only first-born progeny/primogeniture relation; x1 is the first-born daughter of the first-born daughter of ... the first-born daughter of x2, connected by a graph-path passing through intermediate relations/steps (successive first-born daughters) x3 (ce'o; ordered list).
seljavytertau
x1 is a term in binary metaphor/tanru x2 (text) with other element (modifying or being modified by) x3 so as to produce meaning x4 in context/usage/instance x5
tertau
x1 is the modified part/modificand of binary metaphor x2 with modifying part x3, giving meaning x4 in usage/instance x5
xekska
x1 is darkly colored with color x2 [ka]
zgipre
x1=p1=z2 is a musician, associated with music of style/genre/type x2=z1.
ziltau
t1 is a tanru component.
dzoli
x1 is recursively related to x2 by applying x3 (number) levels-of-recursion of the predicate-relation x4 (ka with two ce'u)
dau'a (exp!)
gafyzmico: Reset all default specifications of immediately previous word to official definition specifications hereinafter (permanently)
de'au (exp!)
gafyzmico: Cancellation (permanent) of all defaults in immediately previous word
de'oi (exp!)
Cancellation (instant-/usage-wise; temporary) of all defaults in immediately previous word
doi'a (exp!)
gafyzmico: Reset all default specification of the immediately previous word to their respective discourse-external/official definition specifications for this instance/usage only.
ke'e'u
Locks tanru modification order reversal (does not affect lujvo). {ke'e'unai} restores regular order
ke'oi
reverses modification order of contained tanru (does not affect lujvo).
zi'oi (exp!)
fills and deletes (in the manner as "{zi'o}") all terbri sumti slots of immediately previous (id est: tagged) word that are not explicitly filled with a sumti.
aigne
x1 is an eigenvalue (or zero) of linear transformation/square matrix x2, associated with/'owning' all vectors in generalized eigenspace x3 (implies neither nondegeneracy nor degeneracy; default includes the zero vector) with 'eigenspace-generalization' power/exponent x4 (typically and probably by cultural default will be 1), with algebraic multiplicity (of eigenvalue) x5
malternrorci
x1 is an absent or deadbeat co-parent of x2, the 'primary' parent of whom is x1.
tcuskuue
x1 (lu; quote) is said/expressed by x2, followed by expression x3 (lu; quote), via expressive medium x4, and then continuing on/proceeding/serially resuming to express/say x5 (lu; quote), and then x6 (lu; quote), and then x7 (lu; quote), ... (open-ended terbri structure of arbitrarily many sumti slots).